The present invention relates to tissue anchoring devices and biological vessel suspending devices and to systems and methods utilizing same, which can be used, for example, in treating urinary incontinence associated with abnormal bladder positioning.
Urinary incontinence is characterized by the involuntary loss of urine in individuals. Urinary incontinence affects approximately 13 million people in the United States alone, 85% of them women. Urinary incontinence can be caused by physical stress (stress incontinence) typically brought on by heavy object lifting, coughing, laughing or sneezing, an overactive bladder (typically referred to as urge incontinence) or by an uncontrollable slow leak which is termed flow incontinence, and which is often experienced when complete bladder emptying can not be achieved by an individual. Additional but less common types of urinary incontinence include functional incontinence and unconscious or reflex incontinence.
Of the above causes for urinary incontinence, stress incontinence and urge incontinence are considered the most prevalent. Stress incontinence can be caused by anatomic abnormalities in the positioning of the bladder or bladder neck or by sphincter dysfunction. Urine loss occurs when the intravesical pressure (i.e., the pressure within the urinary bladder) exceeds, even by a small amount, the maximum urethral pressure (i.e., the pressure on the urethra to maintain closure). While the problem of stress incontinence occurs in both men and women, it predominantly occurs in women of childbearing age and beyond.
There are several methods and devices which can be used to alleviate involuntary loss of urine in people suffering from incontinence. Surgery is perhaps the most desirable method in cases of severe incontinence in younger patients. The surgical alternative often involves a procedure whereby the bladder neck is suspended such that the bladder assumes a normal position.
For severe cases of stress incontinence, the surgeon may secure the bladder with a wide sling positioned under the urethra. Such a sling supports the bladder and in addition compresses the bottom of the bladder and the top of the urethra, further preventing leakage.
Abdominal Suspension Procedures
One abdominal suspension procedure is the Marshall Marchetti Krantz (MMK) procedure which is still offered in many medical centers throughout the United States although it is no longer the method of choice.
In the MMK procedure, the bladder neck and urethra are separated from the back surface of the pubic bone. Sutures are placed on either side of the urethra and bladder neck, which are then elevated to a functional position. The free ends of the sutures are anchored to the surrounding cartilage and pubic bone.
The Burch procedure, also known as Burch colposuspension (vaginal suspension), is often performed in conjunction with an invasive surgical procedure such as abdominal hysterectomy (removal of the uterus). During the suspension procedure, sutures are placed laterally (sideways), thus avoiding urethral obstruction and allowing the physician to repair any small cystoceles that may be present. The bladder neck and urethra are separated from the back surface of the pubic bone and the bladder neck is then elevated via lateral sutures that pass through the vagina and Cooper's (pubic) ligaments. The vaginal wall and ligaments are brought together without tension, and the sutures are tied.
Needle Suspension
Needle suspension procedures are simpler to perform and are less invasive than abdominal suspension procedures. Numerous types of transvaginal (through the vagina) needle suspension procedures are known in the art.
In transvaginal needle suspension procedures, sutures are placed blindly through the pubic skin or via a vaginal incision into the anchoring tissues on each side of the bladder neck. The bladder neck is then supported by the sutures, which are tied to the fascia (fibrous tissue) or the pubic bone. Operative times and recovery periods are typically shorter in needle suspension techniques as compared to abdominal suspension procedures.
To enhance tissue anchoring, some needle suspension techniques employ bone anchors such as those provided by the Vesica™ and Intac/Infast™ bladder suspension kits.
Sling Procedures
Patients with severe stress incontinence and intrinsic sphincter deficiency (Type III SUI or weakening of the urethra muscle) may not be treatable via the suspension procedures described hereinabove. Such individuals are good candidates for a pubovaginal sling procedure, which can create the urethral compression necessary to achieve bladder control.
This technique involves the creation of a sling from a strip of tissue taken from the patient's abdominal fascia (fibrous tissue); occasionally, surgeons use a synthetic sling, although urethral erosion appears to be more common when synthetic slings are used.
The strip of fascia is obtained via an incision above the pubic bone. Another incision is made in the front of the vaginal wall, through which the surgeon can grasp the sling and adjust its tension around the bladder neck. The sling is secured in place by sutures which are loosely tied to each other above the incision in the pubic fascia, thus providing a hammock for the bladder neck to rest in.
The pubovaginal sling procedure generally results in high success rates, with bladder control lasting more than 10 years, although complications such as accidental bladder injury, wound infections and prolonged urinary retention severely limit the effectiveness of this technique.
The Vesica™ sling procedure employs two small anchors which are secured into the pubic bone in order to provide stable fixation for a synthetic or natural tissue sling which functions in supporting the urethra, bladder neck and sphincter.
The Precision Tack™ transvaginal anchor system also employs bone anchors which are secured into the backside of the pubic bone via a minimally invasive procedure. These anchors are connected to a sling via sutures, which sling then functions like a hammock, to support the bladder in a functional position.
Although the above described surgical procedures provide solutions to individuals suffering from urinary incontinence, such procedures suffer from several inherent limitations as follows: (i) the use of pubic bone anchors creates a potential for osteitis-pubis; (ii) the use of slings and anchors oftentimes does not improve the intra-urethral pressure differential and as such does not address voiding problems; (iii) suspensions may create the potential for residual urine in the bladder; (iv) improper tensioning of supporting sutures may cause urethral obstruction thus making self-catheterization or additional surgical intervention necessary; (v) most of these procedures require hospitalization; and (vi) surgical procedures which utilize sutures/anchors which are secured to soft tissue or bone do not stretch as the bladder neck angle changes during voiding thus not allowing a correct bladder neck angle when voiding and in addition create a strain upon the supported tissue which can lead to tissue damage and/or support failure.
These limitations of prior art suspension techniques are the major causes underlying a reported 50 to 60% failure rate which is observed therewith following 3 years of service.
In addition, limitations inherent to bladder neck/urethra positioning techniques used by surgeons prior to or during a surgical suspension technique often lead to bladder neck mis-positioning and reduced bladder function.
There is thus a widely recognized need for, and it would be highly advantageous to have, a tissue anchoring device and a biological vessel suspending device which can be utilized for bladder suspension while being devoid of the above limitations. In addition, there is also a widely recognized need for, and it would be also highly advantageous to have, a bladder positioning assembly and a method utilizing same which can be used to correctly position the bladder neck and/or urethra prior to a surgical suspension thereof.